Can you get/see the previous owners records? If sold by a dealer, i think in most states, they are rquired ot give you the previous owner's name. Also, I would get it checked out by a BMW mechanic and get a written pre-purchase statement of items wrong or neededing normal service. Then get them to lower the price.
Thanks,
1995 525i Auto, M50TU 2.5L, EAT chip, 1/95 build, USA, 205/65/15 tires, ASC+T, HID, lumbar, EC Mirror, BMW Alpine 5 radio with BMW-Pioneer CD Changer, abt 236k miles, Oxford Green/Parchment